On-Road truck

Mar 28, 2013

POCLAIN HYDRAULICS continues its development on the On-Road market...

With ten years of experience, and now nearly 10,000 trucks equipped with AddiDrive Assist hydraulic assistance at MAN (Hydrodrive), RENAULT TRUCKS (Optitrack), TERBERG TECHNIK (X-Track), TERRA DRIVE SYSTEMS (EZ Trac), POCLAIN HYDRAULICS continues its development on the On-Road market and will soon equip the range of Arocs trucks made by DAIMLER. Hydraulic technology that has been proven successful in areas as diverse as construction, agriculture, or material handling indeed appears as an alternative to traditional mechanical drives. Hydraulic technology is holding the attention of a growing number of manufacturers of trucks that are facing a request for new solutions to improve vehicle productivity while ensuring lower fuel consumption and emissions. The goal of POCLAIN HYDRAULICS is to use its hydraulic expertise to benefit on-road vehicles and open new opportunities for manufacturers. A hydraulic starter will soon expand the range to allow heavy-duty vehicles with severe duty cycles to achieve the Stop & Start function already widespread on light vehicles.



CleanStart™, the Stop & Start hydraulic system by Poclain Hydraulics 









CleanStart™ is a Stop & Start hydraulic system for high displacement engines. The core of CleanStart™ is a hydraulic starter motor which offers high restart reactivity by directly driving the engine crankshaft. The internal combustion engine may then be cut off during passenger pick-up or drop-off at bus stops and in traffic jams, therefore the bus consumes less fuel and there are no vibrations or noises emitted at low speeds.

CleanStart: a single, compact and lightweight circuit consisting of few components.




  1. Hydraulic starter motor
  2. Hydraulic pump
  3. Hydropack, including:

            3.1 Sequence valve

            3.2 Hydraulic accumulator

            3.3 Tank








1 -The core of the CleanStart™ system: the hydraulic starter motor

Its job is to supply instant torque greater than the engine's resisting torque (inertia and first compressions), i.e. a maximum torque of 560 Nm, delivering a power of 28 kW.

The weight/power ratio is a big advantage brought about by hydraulic motors. The compactness of this starter motor allows for its unique positioning directly on the internal combustion engine crankshaft. This gives it high reactivity (start-up in 0.4 seconds) while reducing energy loss.

 2 – The hydraulic pump ensures pressurization of the hydraulic accumulator for next engine start.               

 3 – The Hydropack, including:

            3.1 - The sequence valve ensures pressurization of an    accumulator by diverting the pump flow for as long as is required for pressurization.

The resulting energy storage (pressurized volume of oil) is designed to supply the hydraulic motor for at least one start-up sequence.

           3.2 - The hydraulic accumulator stores the hydraulic energy required to start up the engine.  As the batteries are not used for every start-up, their service life is preserved. Maintenance-free and entirely recyclable, it also has a very good weight/power ratio compared with batteries.

            3.3 - The tank, containing the oil.

The real results :

  • Improved fuel consumption in relation to the cycle and operating conditions, that can be in excess of 10%
  • Increased safety
  • Comfort (no vibration)
  • Decreased noise
  • Reduced pollutant emissions